Irish:
cealgach: guileful/treacherous also beguiling/alluring.
fealltach: deceitful/treacherous
cleasach: playful; tricky/crafty
Scottish:
Another word for "insidious" is the word "treacherous"[or "sly",or "crafty"].
Morrie's disease "ALS" is insidious .
the investigators uncovered an insidious scheme to rob people of their money
You divide it like this: in-si-di-ous.
Scottish Gaelic is a 'coimhead.Irish Gaelic is cuma.
Insidious
No Gaelic word for Chalmers.
It is not a Gaelic word.
In IRISH Gaelic the word is "vaidhtéaraí";in SCOTTISH Gaelic: ?
The word 'bassett' is not a Gaelic word, and therefore has no meaning in Gaelic.
I've been to several specialists and no one can cure this insidious rash.
The investigators uncovered an insidious scheme to rob people of their life savings. Another one is "There is a more insidious threats to Gulf stability."