Rashi 16a DH Tibadek:
1) [line 6] VESTOS D'ORAISA - A woman is obliged by Torah law (Halacha l'Moshe mi'Sinai) to check herself at her Onah (the fixed interval when she usually menstruates). If the Onah passed and she did not check herself she is assumed to be Tamei even if a later Bedikah is clean.
2) [line 7] HUNA CHAVRIN - see Kesuvos 69a
3) [line 16] ORE'ACH/ORACH BI'ZMANO BA - the period comes in its time (according to the Aruch this word is read Ore'ach; however, see Breishis 18:11 Orach ka'Nashim)
4) [line 20] K'SHI'UR VESES - immediately
7) [line 37] MAKOR, MEKOMO TAMEI - the place of the Makor is Tamei and makes *any* blood that passes through Tamei, even the blood of a wound
8) [line 6] TECHAPENAH - shall cover it
9) [line 8] AD SHEHA'ROK B'SOCH HA'PEH, SHEMA NIMOK V'HOLECH LO - perhaps while the saliva (blood) was still in the mouth (vagina) it disintegrated and disappeared
10) [line 12] HE'ERACHTA ALEINU - you were Machmir on us
*12*) [line 21] ASURAH L'SHAMESH - According to what Rashi said at the end of the first Perek, this Gemara must be referring exclusively to a woman who handles Taharos.
13) [line 23] MOCHICHAH KAYAM - her evidence exists
15) [line 41] SEFER BEN SIRA - An ancient work comprising part of the Apocrypha, written around 320 B.C.E. According to tradition, Ben Sira was a son of the prophet Yirmiyahu.
16a) [line 42] NIRGAL - regularly found