IPA: /ˈnʌkli/
KK: /nʌkli/
Having a shape or appearance similar to a knuckle.
The knuckly branches of the tree made it difficult to climb.
The word 'knuckly' originates from 'knuckle' (from Middle English 'knokel', meaning a joint of the finger) combined with the suffix '-y' (meaning characterized by). Thus, 'knuckly' describes something that is characterized by knuckles or has knuckle-like features.
Think of 'knuckle' as the joint of your finger, and remember that 'knuckly' means something that has features like knuckles.