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, the sixth-century king said to have drowned nearby; Carrick-on-Shannon's rock is the one the ford crossed. It is one of the most reliably literal elements in the language.
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, the sixth-century king said to have drowned nearby; Carrick-on-Shannon's rock is the one the ford crossed.
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).