buoy
1. buoy \'bu:-e-, 'bo.i\ n [ME boye, fr. (assumed) MF boie, of Gmc origin;
akin to OE be]-acen sign - more at BEACON 1: FLOAT; esp : a floating object
moored to the bottom to mar k a channel or something (as a shoal) lying
under the water 2: LIFE BUOY
2. buoy vt 1: to mark by or as if by a buoy 2a: to keep afloat 2b:
SUPPORT, SUSTAIN {hope ~s him up} : FLOAT
Webster's English Dictionary