代数幾何学: algebraic geometry

specialist; expert

代書: amanuensis, scribe / 代署: sign for another

大翔: a male given name

代償: vicarious compensation / 大小: large and small; size; long and short swords / 大将: general, admiral, boss / 大証: Osaka Securities Exchange / 代将: brigadier general, commodore

大伸: a male given name

大介, 大輔, 大昌, 大祐, 大助, 太亮: a male given name

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend