IPA: /ˈkwɔːr.əl.sə.mli/
KK: /ˈkwɔrəlˌsəʊmli/
In a way that involves arguing or fighting with others.
The siblings quarrelsomely debated over who would get the last piece of cake.
Quarrelsomely → It is formed from "quarrel" (from Old French *quarrel*, meaning a dispute or argument) and the suffix "-some" (meaning inclined to) combined with "-ly" (meaning in a manner). The word "quarrelsomely" means in a manner inclined to cause disputes or arguments.
Think of someone who is 'inclined' ('-some') to get into 'arguments' ('quarrel') — that's why quarrelsomely means behaving in a way that leads to disputes.