a-swimadv.

/əˈswɪm/Etymology: a prep.1 + swim n.
the world > movement > progressive motion > moving with current of air or water > movement in or on water > [adverb] > moving freely on surface
1870 W. Morris I. i. 125 The shallow flowing sea..set the wrack a-swim.
This entry has not yet been fully updated (first published 1885; most recently modified version published online June 2018).