Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
sesquĭ-pēs, pĕdis, m., a foot and a half (in length, breadth, etc.): cytisum in sesquipedem ponere, Varr. R. R. 1, 43: plus quam sesquipedem prohibeat infodere, Col. 3, 13, 8; id. Arb. 1, 5: sesquipede est quam tu longior, Plaut. Trin. 4, 2, 58; Mart. 8, 60, 2; Pers. 1, 57.