In Cnósach Fócal ó Bhaile Bhúirne p71, there is this:

"crios-iarracht do thúirt (dá chois, etc) ar rod".

This follows the entry on "crios" meaning " a lashing with a belt".

Does anyone know what crios-iarracht means?

I can only find "iarracht" as meaning "strike" in Foclóir.

What is "do thúirt"? It seems like the past tense of "abair" in Scottish Gaelic.

do thúirt is "do thabhairt" - it is how it is pronounced in Munster Irish.

I've found out the meaning of this. As in English, "belt" can mean, not just a leather belt, but a blow, a strike. ("I belted him in the face"). Crios-iarracht a thabhairt means "to draw a blow, attempt to hit".

[It'd be interesting to know if this use of belt in English comes from Irish.]