Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
sesquĭ-plex, plĭcis, adj. [plico], taken once and a half; once and a half as much: sesquiplex aut duplex aut par, * Cic. Or. 57, 193; also sescuplex (cf. sescuplus), Quint. 9, 4, 47.