This study aims to track diachronic semantic shift in a small set of monomor-phemes collected from the Oxford English Dictionary (OED), carrying the initial fl-phonestheme, such as flounder, flummox, flail, etc. The purpose is to determine the semantic behavior of fl-monomorphemes by identifying OED key words, which are then classified into eleven conceptual categories of semantic features. Five features of the eleven are conjectured as major on the basis of frequency of occurrence and frequency of combination with other features. Features which share similar progression rates are hypothesized to be linked through the natural process of metonymy (MTA, SV, SBT). Early emergent features are viewed as primary (MTA and MTL). From there, directionality of shift is assessed by comparing co-emergent with post-attestation features. Although no general pattern is discernible on this scale, several case studies of unexpected semantic shift towards minor features as in flummer and flourish show promising results for the field of historical lexical semantics.