[buoy] n [ME boye, prob. fr. MD boeye; akin to OHG bouhhan sign--more at beacon] (13c) 1: float 2; esp: a floating object moored to the bottom to mark a channel or something (as a shoal) lying under the water
2: life buoy
[2]buoy vt (1596) 1: to mark by or as if by a buoy
2. a: to keep afloat b: support, uplift "an economy ~ed by the dramatic postwar growth of industry --Time"
3: to raise the spirits of--usu. used with up "hope ~s him up" ~ vi: float--usu. used with up