Crabbed means bad-tempered, or cramped and hard to read. A crabbed old man, crabbed handwriting, a crabbed reply.
The two senses come from the same image — the crab's sideways awkwardness — and the handwriting sense is the one most often met, in descriptions of old documents. Note that it is two syllables when it means bad-tempered.
1adjectivecrabbedBad-tempered, or cramped and hard to read.
“The letter was written in a crabbed hand that I could barely read.”
crabbed is a quality of manner or writing.
Crab plus -ed, from the animal's sideways gait and awkward look.
Middle English
crabbed
English, today
crabbed
From Middle English crabbed; equivalent to crab + -ed.
Etymology from Wiktionary, CC BY-SA