It is an alteration of the phrase "p*t*ng ina mo", meaning "m*therf*cker" or "your mother is a prostitute." Obviously it is some sort of curse. It is used to make fun of people who do not know Filipino language.

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed

"Put tank in a mall" is a play phrase for "putang ina mo" which is a Pilipino vulgarity that means fuck your mother.

Often used on Dota 2

Put tank in a mall is a word play. It is originally a Filipino foul word (phrase) "putang ina mo" which literally means "your mom's a whore". Put tank in a mall is often used in DOTA2 when Filipinos are asked to speak in English.