From pikros (bitter). To make bitter, to embitter, to produce bitterness. Paul warns husbands not to be harsh (embittered) with their wives.
Paul commands: 'Husbands, love your wives and do not be harsh with them' (Colossians 3:19). The word implies a pattern of bitterness that poisons the relationship. In Revelation, the waters become bitter at the trumpet judgment (Revelation 8:11). Bitterness — whether in marriage or in the soul — is toxic and destructive.