sŭb-ămārus, a, um, adj.,
somewhat bitter , bitterish (Ciceronian), Cic. Fat. 4, 8. —Adverb.: subamarum arridens, somewhat bitterly , Amm. 27, 11, 5.
sub-amārus adj., slightly bitter: aliqua res. —Plurn. as subst: alios subamara delectent...
An Elementary Latin Dictionary