also: へちむくれ · へしむくれ · へちゃもくれ · へちむくり
noun
ugly person; unattractive person
Derogatory term for someone considered physically unattractive. Strongly insulting; avoid in polite conversation.
あいつはへちゃむくれだから、誰も相手にしない。
Nobody pays attention to him because he's so ugly.
Derogatory term for a cowardly or weak person. Less common than the 'ugly' sense; may be dated or dialectal.
へちゃむくれのくせに、偉そうな口をきくな。
Don't talk big when you're just a coward.
いくじなし is a standard term for a coward or spineless person, without the physical ugliness connotation of へちゃむくれ.
The exact derivation is uncertain. It may be a compound of へちゃ (onomatopoeic for flatness or ugliness) and むくれ (from むくれる, to become sullen or distorted), but this is speculative.