fast (adj.)
constant, firm, steadfast
2H6 V.ii.21[York to Clifford] thou art so fast mine enemy
3H6 IV.i.119[George to Edward] farewell, and sit you fast
3H6 V.ii.3[Edward as if to Montague] sit fast; I seek for thee [i.e. look out]
Cym I.vii.138[Iachimo to Innogen] I ... will continue fast to your affection, / Still close as sure
Oth I.iii.357[Roderigo to Iago] Wilt thou be fast to my hopes
SHAKESPEARE'S WORDS © 2018 DAVID CRYSTAL & BEN CRYSTAL