Gina DC: Continuity Cop

Teutonic, hlak-, hrok-, hring-:
Goth. hlahjan, O.N. hlakka, O.H.G. hlah-han N.H.G. lachen, A.S. hleh-han, M.E. hlе3еп, lauhwen, laughen, (to laugh), A.S. hleahtor, (laughter), Goth. hrecks, (cawing as a raven), O.H.G. hruoh, O.N. hrok-r, A.S. hroc, (a rook), O.N. hringa, A.S. hringan, (to wring), O.H.G. glocka, N.H.G. glocke, O.N. klukka, Swed. clocka, A.S. clocge, M.E. clokke, clok, (a clock, a bell).

Celtic, Wel. cricciad, (a cricket), Wel. cricellu, (to chirp), Bret. kloch, Ir. clog, (a bell), Gael. clog, clag, Manx clagg, (a bell), Ir. cloguim, (I ring), Wel. cleca, (clack), Gael. cearc, Ir. cerc, cearc, (a hen).

English Derivatives:
Latin - clang, clangour
L. Latin and Romance - cricket (the insect), clock, cloak (from Celtic)
Teutonic - laugh, laughter, rook, rookery, ring

BALY, J. 'Eur-Aryan roots: With their English derivatives and the corresponding words in the cognate languages compared and systematically arranged', 1898. (p 187)

German (also Röker): of uncertain origin. In the north, it may be from a short form of a Germanic personal name from hrok ‘rook’, or alternatively from an agent derivative of Middle Low German rok ‘smoke’ and hence an occupational name for someone who smoked fish or meat or for a blacksmith or charcoal-burner. In the east it could be an occupational name for a beekeeper, from Slavic roj ‘swarm of bees’. (http://www.ancestry.com/facts/Roker-name-meaning.ashx)

Deriv names: Roc (Catalan), Rocco (Italian), Roch (French, Polish), Rochelle (French), Rochus (Dutch), Rokus (Frisian), Roque (Portugese)

rok is 'year' in Polish.