Something not duplicated, being singular

existence / being; entity

exist

technology; technique; technical

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

one and only; unparalleled; matchless; without equal

one's presence as felt by others

technician, engineer