Crossword puzzle clue "times to study"

to pack tightly

NERD, a person obsessed with computers at the expense of human interaction, also NURD

ERA, a main division of geological time

(Greek) the repetition of a word or expression at the beginning of successive phrases, clauses, sentences or verses esp. for rhetorical effect, also ANAPHOR, EPANAPHORA

CUBE, to raise to the third power

the cardinal number one above seven

(archaic) old age, also EILD