HD stands for Hold for a reliever
The abbreviation "HD" basically stand for High Definition.
High
Heavy duty
High Definition
Heavy Duty
The "HD" stand for harddrive, not high defenition.
High Fidelity, it was the old school "HD" for audio.
In context of television definitions, with HD standing for high definition, SD stands for standard definition - meaning all non-HD televisions signals.
The initials "HD" can stand for several things, but most commonly, they refer to "High Definition," which is used to describe video or image quality with improved resolution compared to standard definitions. In other contexts, HD can also refer to "Hard Disk" in computing or "Huntington's Disease" in medical terminology. The specific meaning usually depends on the context in which it is used.
A&E HD ABC Family HD Cartoon Network TBS in HD Sci Fi HD Dish Network Pay-Per-View HD NFL Bio HD Food Network HD Theatre HDNet ESPN HD ESPN2 HD ESPNews HD Bravo HD National Geographic HD HDTV HD History HD Lifetime HD USA HD Disney HD Travel Net HD Animal Planet HD Versus HD Hallmark HD CNBC HD+ CNN HD Discovery HD TLC HD TNT HD Dish Network On Demand
GBL in Baseball means "Golden Baseball League
a stand up double in baseball is when the batter hits a double and doesn't have to slide at second.