ETYMOLOGY
from sleuth (sloth, laziness obs.) + -ful
EXAMPLE
“…And he þat hauys greet egℏen̛ ys enuyous & witℏ-outen shame, sleuthful, and vnobeyssant. He þat hauys lityƚƚ eghen̛, lyk to heuenly colour, or blake, ys of sharpe vnderstondynge, curteys, and leel…”
From: Secreta Secretorum,
(a treatise which purports to be a letter from Aristotle to his student Alexander the Great on an encyclopedic range of topics, including statecraft, ethics, physiognomy, astrology, alchemy, magic, and medicine)
Lexicophilia 