Is it ensure, insure, or assure?
"sew together loosely," c.1400, from Old French bastir "build, construct, sew up (a garment), baste, make, prepare, arrange" (12c., Modern French bâtir "to build"), probably from a Germanic source, from Proto-Germanic *bastjan "join together with bast" (cf. Old High German besten; see bast).
"to soak in gravy, moisten," late 14c., of unknown origin, possibly from Old French basser "to moisten, soak," from bassin "basin" (see basin). Related: Basted; basting.
To strike violently and repeatedly: he basted the dog after it misbehaved (1530s+)