GC: adj

S: https://www.learnthat.org/dictionary/5240_cankerous.html (last access: 22 September 2016); http://www.wordfocus.com/word/cankerous/ (last access: 22 September 2016).

N: 1. 1535-45; canker + -ous.
2. cankerous ‎(comparative more cankerous, superlative most cankerous).
Infected with canker; ulcerous.
Causing canker; ulcerating.
3. canker (n): Middle English (denoting a tumour): from Old French chancre, from Latin cancer crab.
An ulcerous condition or disease of a human or animal, in particular.
North American A small ulcer of the mouth or lips.

S: 1. http://www.dictionary.com/browse/cankerous (last access: 22 September 2016). 2. https://en.wiktionary.org/wiki/cankerous (last access: 22 September 2016). 3. https://en.oxforddictionaries.com/definition/canker (last access: 22 September 2016).

SYN: ulcerous

S: https://en.wiktionary.org/wiki/cankerous (last access: 22 September 2016); http://www.wordfocus.com/word/cankerous/ (last access: 22 September 2016).

CR: infestation, psoriasis, ulcer.