A word made-up by the transformers fandom. They are suppose to be "baby" transformers. Normally this word is used by retarded fans. Robots don't have babies because they are made as adults.
SPARKLINGS ARE NOT REAL! THEY ARE MADE-UP BY THE FANDOM! Transformers cannot have kids because they do not have gender. Only frames and personalities that make them seem like they have gender.
Fan 1: OMG My OC and Starscream are in laaaav they need sparklings!
Sane Fan: What?
Fan 1: Sparklings! Babies!
Sane Fan: Robots can't have babies.