As adjectives the difference between cunning and adaptable

is that cunning is sly; crafty; clever in surreptitious behaviour while adaptable is capable of adapting or of being adapted.

As a noun cunning

is (obsolete) knowledge; learning; special knowledge (sometimes implying occult or magical knowledge).

In uncountable terms the difference between union and board

is that union is the state of being united or joined while board is regular meals or the amount paid for them in a place of lodging.

As nouns the difference between union and board

is that union is the act of uniting or joining two or more things into one while board is a relatively long, wide and thin piece of any material, usually wood or similar, often for use in construction or furniture-making.

As a verb board is

to step or climb onto or otherwise enter a ship, aircraft, train or other conveyance.

In intransitive terms the difference between invest and infuse

is that invest is to make investments while infuse is to undergo infusion.

As verbs the difference between invest and infuse

is that invest is to clothe or wrap (with garments) while infuse is to cause to become an element of something; to insert or fill.

As a noun invest

is an unnamed tropical weather pattern "to investigate" for development into a significant (named) system.