How can........

[deeahgwitch]

Any genealogists on this thread ?
I know the wonderful Professor Turi King is sometimes on it.
How can my DH's mother's first cousin's son be a closer match to him ( is that a first cousin once removed or a second cousin? ) than his mother's grandson - his half sister's son.

First cousin of DH's mother's, son shares 714 cm
DH's half sister's son shares 620cm.

There's a range for each category, Try inputting the cms here:
DNA Painter | Shared cM Project 4.0 tool v4 with relationship probabilities

@deeahgwitch Your DH and the relative are second cousins as they are the same generation. You use the once/twice removed thing to describe people who are a generation apart. If the second cousin has children, then your DH will be second cousin once removed to them, and if you and your DH have children, then all the children are third cousins.

Thank you