Rock. Written Carrick, Carrig, Carrick — the same Irish word, carraig, in the spellings English gave it.
Carraig is a rock (a crag, an outcrop, a boulder in a river) and Carrick- names describe exactly that. Carrickfergus is the rock of Fergus, traditionally a king said to have been shipwrecked there. Carrick-on-Shannon is the warning case: its Carrick is a corruption of cora, a weir (Cora Droma Rúisc), not a rock at all.
Source: P. W. Joyce, The Origin and History of Irish Names of Places (1869–1913) · Logainm ↗
Rock: it is the Irish carraig. Carraig is a rock (a crag, an outcrop, a boulder in a river) and Carrick- names describe exactly that. Carrickfergus is the rock of Fergus, traditionally a king said to have been shipwrecked there.
carraig. English spellings of the same word include Carrick, Carrig, Carrick, because the names were written down by ear.
Carrick-on-Shannon (Cora Droma Rúisc), Carrickfergus (Carraig Fhearghais), Carrickmacross (Carraig Mhachaire Rois), Carrick-on-Suir (Carraig na Siúire).