In English, Aeschylus is almost never a living given name. It is a proper noun that, for nearly every reader, names one person: the Athenian dramatist of the early fifth century BCE, the oldest of the three tragedians whose plays still survive in any number. Lexicons treat the English word as that name, and they list a derived adjective, Aeschylean, for work that sounds or feels like his. Anyone hunting the origin of the word aeschylus is therefore chasing a learned personal name, not a native English common noun.
A scholar's spelling, not a street word
The form did not travel through Old English households. English took it as a learned borrowing from the Latin nominative Aeschylus, which is itself a letter-for-letter rendering of Ancient Greek Αἰσχύλος. The conversion follows a familiar classical recipe. Greek αι was written ae in Latin; Greek υ was written y; the masculine ending -ος became Latin -us. The same pipeline gives English Aesop and Aeneas. Older title pages often used the ligature Æschylus; modern print usually splits that character into ae. Both spellings are the same Latin sequence.
Western Europe first had a printed Greek text of the poet in 1518, when the Aldine press in Venice issued a Latin-titled volume of his tragedies. From that point the name circulated among humanists in Latin even when the plays themselves were read in Greek. English translations arrived later; Robert Potter's late-eighteenth-century version still wore the ligature on the title page. Because the word entered English already glued to one famous bearer, it did not need a new denotation. It simply became the standard English label for that playwright, with a rare secondary use as a historical given name.
The Greek name was not unique to him. Other men in antiquity were called Αἰσχύλος, just as other men were called Αἰσχίνης. English usage narrowed. Once the tragedian stood at the head of the surviving tragic canon, the Latinized spelling in English pointed to him unless a writer went out of the way to mark a different bearer.
The Attic name and the stem for shame
Αἰσχύλος belongs to a well-attested Greek family built on αἰσχ-. The Homeric noun αἶσχος covers public disgrace and, in later prose, ugliness of body or of character. Beside it stand αἰσχρός, shameful or ugly; αἰσχύνω, to put someone to shame; and αἰσχύνη, shame as an inward feeling. The same stem yields another Latinized English name, Aeschines, borne by the fourth-century Athenian orator. Hjalmar Frisk's etymological lexicon of Greek lists Αἰσχύλος among the forms that keep an old u-stem of this family, the vocalism also visible in αἰσχύνω.
The suffix -υλος is a common Greek hypocoristic ending, used to fashion a familiar or shortened personal name. Read that way, Αἰσχύλος is a diminutive on the shame-or-ugliness stem. Handbooks sometimes paraphrase the result as a nickname meaning a little ugly person. That is a reconstruction of how such names were formed, not a documented story about the poet's childhood. Unflattering and ironic given names were ordinary in Greek; the morphology is plausible. It is not a proven private joke about this particular man.
A few lexical notes float a rival cut: a negative prefix plus ἰσχύς, strength. That analysis has not carried the field. The usual privative before a vowel is ἀν-, not a simple ἀ-, and the αἶσχος family already explains both the consonants and the u-vowel. The strength reading can stand as a minority guess.
Deeper than Greek, the picture fades. An older comparison of αἶσχος with Gothic aiwiski, a word for shame, is now generally given up because the sound correspondences are forced. Other scholars have looked toward the Greek verb of shame αἰδέομαι, or even toward Kartvelian words of similar sense. None of those links is firm enough to treat as the next layer under the English name. Responsible history stops at the Greek stem.
What English did, and did not, do with the word
Aeschylus did not drift from one English meaning to another. It never became a trade term, a slang insult, or a dead metaphor in everyday speech. The changes that did occur are orthographic and scholarly. Printers dropped the ligature. Classicists sometimes prefer Aischylos, a spelling closer to the Greek, which is the ordinary form in German and in several other European languages. French Eschyle, Italian Eschilo, Spanish Esquilo, and Russian Эсхил are the same Latin-Greek name after each language applied its own habits to ae and to the ch. Modern Greek keeps Αισχύλος.
The one productive English offshoot is the adjective Aeschylean. It means of or like the poet, and by a mild extension it can describe drama that is large in scale, stark in tone, or occupied with inherited guilt and divine justice. That is an expansion of the personal name, not a survival of the old Greek noun for disgrace.
English pronunciation moved still further from Attic. Most English speakers begin the name with an e-vowel, as in the first syllable of elegant, and they treat the ch as a hard k. The Attic form opened with a diphthong ai and an aspirated k. The gap is the ordinary fate of a name that arrived on the page, through Latin letters, rather than by ear.
The epitaph and the stem
Tradition holds that the poet's grave at Gela named him as an Athenian who had fought at Marathon and said nothing about the stage. Whether he wrote those lines or not, the contrast is useful for the word itself. English Aeschylus carries a Greek stem that once meant shame or unloveliness, yet the English word never meant that. It means the man, and then, in the adjective, the manner of his plays. The durable fact is morphological: the u-stem of αἶσχος, passed through Latin ae, still sits in English beside Aeschines and the Greek vocabulary of shame.