deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE

/ap- / अप्

The nounbase **ap- अप् means "waters".

apAm अपाम् apsu अप्सु

(Not to be mixed up with the /ap' affix.)

/ap- lengthens its vowel before /jas by aptRntRcsvas..., but not before /zas.

ApaH आपः apaH अपः

It becomes ad अद् before /bhis /bhyas /bhyAm by apobhi.

adbhiH अद्भिः adbhyas अद्भ्यस्

According to /varadarAja it always takes plural terminations.

But, as /pANini doesn't say "plural only", you may feel free to use Ap आप् Apam आपम् apA अपा... anyway.