contrivance vs lash-up

contrivance and lash-up both are nouns.

Word	Noun	Adjective	Verb	Adverb
contrivance	Yes	No	No	No
lash-up	Yes	No	No	No

As nouns, contrivance and lash-up are synonyms defined as:

contrivance (noun)	lash-up (noun)
the act of devising something	any improvised arrangement for temporary use
a device or control that is very useful for a particular job
any improvised arrangement for temporary use
an elaborate or deceitful scheme contrived to deceive or evade
the faculty of contriving; inventive skill
an artificial or unnatural or obviously contrived arrangement of details or parts etc.