The difference between Boo-boo and Nick

When used as nouns, boo-boo means a mistake or error, whereas nick means a particular place or point considered as marked by a nick.

When used as verbs, boo-boo means to defecate, whereas nick means to make a nick or notch in.

check bellow for the other definitions of Boo-boo and Nick

Boo-boo as a noun (countable, colloquial, often, childish):

A mistake or error.
Boo-boo as a noun (countable, colloquial, childish, by or to young children):

A minor injury, such as a cut or a bruise.
Boo-boo as a noun (uncountable, colloquial, childish, by or to young children):

Feces.

Boo-boo as a verb (colloquial, childish, by or to young children):

To defecate.

Nick as a noun (now, rare):

A small cut in a surface. A particular place or point considered as marked by a nick; the exact point or critical moment. A notch cut crosswise in the shank of a type, to assist a compositor in placing it properly in the stick, and in distribution.

Examples:

"[[in the nick of time in the nick of time]]"
Nick as a noun (cricket):

A small deflection of the ball off the edge of the bat, often going to the wicket-keeper for a catch. One of the single-stranded DNA segments produced during nick translation. The point where the wall of the court meets the floor.
Nick as a noun (Britain, slang):

In the expressions in bad nick and in good nick: condition, state.

Examples:

"The car I bought was cheap and in good nick."
Nick as a noun (Britain, law enforcement, slang):

A police station or prison.

Examples:

"He was arrested and taken down to Sun Hill nick [police station] to be charged."

"He’s just been released from Shadwell nick [prison] after doing ten years for attempted murder."

Nick as a verb (transitive):

To make a nick or notch in; to cut or scratch in a minor way. To make ragged or uneven, as by cutting nicks or notches in; to deface, to mar. To make a crosscut or cuts on the underside of (the tail of a horse, in order to make the animal carry it higher).

Examples:

"I nicked myself while I was shaving."
Nick as a verb (transitive, obsolete):

To fit into or suit, as by a correspondence of nicks; to tally with. To hit at, or in, the nick; to touch rightly; to strike at the precise point or time. To hit the ball with the edge of the bat and produce a fine deflection. To throw or turn up (a number when playing dice); to hit upon.
Nick as a verb (transitive, Australia, Britain, slang):

To steal.

Examples:

"Someone’s nicked my bike!"
Nick as a verb (transitive, Britain, law enforcement, _, slang):

To arrest.

Examples:

"The police nicked him climbing over the fence of the house he’d broken into."

Nick as a noun (Internet):

Examples:

"a user’s reserved nick on an IRC network"

Nick as a verb (transitive, obsolete):

To give or call (someone) by a nickname; to style.