[ない, nai](adj-i) (1) (uk) (See 亡い) nonexistent; not being (there); (2) unpossessed; unowned; not had; (3) (See またとない) unique; (4) (as ...ことがない, etc.) indicates negation, inexperience, unnecessariness or impossibility; (aux-adj) (5) (See ない) (after the ren'youkei form of an adjective) not ...; (6) (after the -te form of a verb) to not be...; to have not ...; (P)#952[Add to Longdo]
[ないと, naito](exp) (1) (uk) (abbr) (col) (See ないと行けない・1) (after negative base of verb) have to (verb); must (verb); (2) (See ないと行けない・2) is indispensable; absolutely necessary[Add to Longdo]