word forming element indicating "oneself," also "automatic," from Old English use of self (pron.) in compounds, such as selfbana "suicide," selflice "self-love, pride, vanity, egotism," selfwill "free will." Middle English had self-witte "one's own knowledge and intelligence" (early 15c.).
OED counts 13 such compounds in Old English. Middle English Compendium lists four, counting the self-will group as a whole. It re-emerges as a living word-forming element mid-16c., "probably to a great extent by imitation or reminiscence of Greek compounds in (auto-)," and formed a great many words in the pamphlet disputes of the 17c.
1630s, "to make larger, increase," from French agrandiss-, present-participle stem of agrandir "to augment, enlarge" (16c.), ultimately from Latin ad "to" (see ad-) + grandire "to make great," from grandis "big, great; full, abundant" (see grand (adj.)). The double -g- spelling in English (also formerly in French) is by analogy with Latin words in ad-. Related: Aggrandized; aggrandizing.
<a href="https://www.etymonline.com/word/self-aggrandizing">Etymology of self-aggrandizing by etymonline</a>
Harper, D. (n.d.). Etymology of self-aggrandizing. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/self-aggrandizing