The difference between Hero sandwich and Sub

When used as nouns, hero sandwich means a large sandwich on a long thick bun, whereas sub means a submarine.

Sub is also preposition with the meaning: under.

Sub is also verb with the meaning: to substitute for.

check bellow for the other definitions of Hero sandwich and Sub

Sub as a noun:

A submarine.
Sub as a noun:

A submarine sandwich: a sandwich made on a long bun.

Examples:

"We can get subs at that deli."
Sub as a noun (informal):

A substitute, often in sports.

Examples:

"With the score 4 to 1, they brought in subs''."

"She worked as a sub until she got her teaching certificate."
Sub as a noun (British, informal, often in plural):

A subscription: a payment made for membership of a club, etc.
Sub as a noun (informal):

A submissive in BDSM practices.
Sub as a noun (Internet, informal):

A subtitle.

Examples:

"I've just noticed a mistake in the subs for this film."
Sub as a noun (computing, programming):

A subroutine (sometimes one that does not return a value, as distinguished from a function, which does).
Sub as a noun (colloquial):

A subeditor.
Sub as a noun (colloquial):

A subcontractor.
Sub as a noun (colloquial, dated):

A subordinate.
Sub as a noun (colloquial, dated):

A subaltern.
Sub as a noun (colloquial):

A subscription to an online channel or feed.
Sub as a noun (colloquial):

A subscriber to an online channel or feed.

Sub as a verb (US, informal):

To substitute for.
Sub as a verb (US, informal):

To work as a substitute teacher, especially in primary and secondary education.
Sub as a verb (British, informal, football):

To replace (a player) with a substitute.

Examples:

" He never really made a contribution to the match, so it was no surprise when he was subbed at half time."
Sub as a verb (British, informal, football):

Less commonly, and often as sub on, to bring on (a player) as a substitute.

Examples:

"He was subbed on half way through the second half, and scored within minutes."
Sub as a verb (British):

To perform the work of a subeditor or copy editor; to subedit.
Sub as a verb (UK, slang, transitive):

To lend.
Sub as a verb (slang, intransitive):

To subscribe.
Sub as a verb (BDSM):

To take a submissive role.

Sub as a verb:

To coat with a layer of adhering material; to planarize by means of such a coating.
Sub as a verb (microscopy):

To prepare (a slide) with an layer of transparent substance to support and/or fix the sample.