bouldering

or bowl·der·ing

[ bohl-der-ing ]
/ ˈboʊl dər ɪŋ /

noun

pavement made with small boulders.

Origin of bouldering

1875–80; boulder to pave with boulder(s) + -ing1

British Dictionary definitions for bouldering

bouldering
/ (ˈbəʊldərɪŋ) /

noun

rock climbing on large boulders or small outcrops either as practice or as a sport in its own right