Each group of three definitions describes three words that are spelled the same, except for one letter (each group describes a different set of words). Example: king, ring, wing.

1a) a bone in the leg
1b) arboreal mammal, common to Madagascar
1c) to take exception or object

2a) a mixture of liquids, as for medicine
2b) a liquid preparation for cosmetic use
2c) an opinion or view

3a) something having a spiral or twisted form
3b) to hold back or restrain
3c) the thick part of coagulated milk

4a) to beat or damage with repeated blows
4b) to trade by exchange of goods
4c) good-natured witty joking