wading bird (Crocethia alba), c. 1600, probably from sand (n.) + diminutive suffix -ling, but OED suggests possible derivation from Old English *sand-yrðling, with second element yrðling "plowman" (literally "earthling").
sandbar
sand-blast
sandblind
sandbox
sand-castle
sanderling
sand-fly
sandiness
Sandinista
sand-lot
sandman