Extended Strong's Greek Lexicon (Abbott-Smith based)
bitterly
Usage: πικρῶς adv. (πικρός), [in LXX for מַר, מָרַר pi. ;] bitterly: metaphorically, (cf. πικρὸν δάκρυον, Hom.), ἔκλαυσε π., Mat.26:75, Luk.22:62 (see MM, xviii, see word παρακολουθέω).† (AS)