Latin labor "work." This word prevails even today in Italian as lavoro "work." The verb based on the Latin noun, "laborare," is the source of "laboratory," from Latin laboratorium "workplace." "Elaborate" comes from Latin elaborare "to work out" from ex "out" + laborare "work."1
kâr e ranj-âvar / saxt / tavân-farsâ / por-dard-o-dud
+
It is, in fact, a call to reason, again to undertake the most laborious of all tasks--that of self-examination, and to establish a tribunal, which may secure it in its well-grounded claims, while it pronounces against all baseless assumptions and pretensions, not in an arbitrary manner, but according to its own eternal and unchangeable laws. This tribunal is nothing less than the critical investigation of pure reason.
(E. KANT,
The Critique of Pure Reason)
2
ranj
+
fra. fruit de son labeur : dast-ranj aš
(เพน'สเทคคิง) adj. อุตสาหะ,ระมัดระวัง ตัวอย่าง: (Embroidery takes painstaking skill)
['peinz,teiki¤] I. а старателен, усърден, прилежен; ревностен; щателен; II. п старание, усърдие, прилежание.