rocky

Middle English rokki was built on rok, a word that could mean a stone, a rock by the sea, a mountain outcrop or even a stronghold. It is one of three adjectives spelled rocky, and the only one that has to do with stone. It compares both ways, rockier or more rocky, and it is the word for terrain: a rocky shore, a rockier stretch of trail.

A figurative stretch of the "wobbly" meaning: what is rocky here sways and threatens to tip, the way a relationship or a business does when it may not last. The word suits stretches of time and beginnings, as in rocky times, a rocky start or a rocky few months, and unsteady is the synonym that keeps its image best.

The swaying verb rock lies behind this meaning, not the stone: Middle English rokken was what one did to a cradle, and also what an unsteady thing did by itself. A rocky table, ladder or canoe tips when it is touched or shifted, and wobbly and tottering are its close synonyms.

A use that began in American English, and it describes a passing state, not a lasting trait: a person feels rocky for a while, after a shock or during an illness, and steadies again on recovering. Shaky is the close everyday synonym; unnerved leans toward the shock, and weakened toward the illness.

Here the word compares a thing to rock itself, where the "full of rocks" meaning describes ground covered in it. Lloyd Pye's Mismatch (1988) stretches the idiom between a rock and a hard place into "the rockiest rock and the hardest hard place you ever imagined." Rocklike, stonelike and flinty say the same thing without the play on words.

Rock the music, plus the adjective ending -y, so neither stone nor sway plays any part here. It grades easily, as words for a sound do: an album can be quite rocky, or rockier than the band's last. Rockish and rockesque are its near synonyms.