opsimath UK /ˈɒpsɪmæθ/US /ˈɑpsɪmæθ/ noun1 •(rare) A person who learns late in life.But with reference to the latter, I may be permitted to say, that from the dissipation and idleness of his earlier years, Mr. Fox in Greek and Roman Literature was necessarily an Opsimath. — 1808 formsopsimaths