LOL. It’s handy shorthand for laughter, or the harbinger of an intellectual apocalypse, depending on who you ask. Its part of speech is also debated: spelled out, it’s an initialism, but if you pronounce it as a word, it’s an acronym.
“But I don’t use it at all!” you might say. “I am too smart to use an asinine word like LOL!” Maybe you are, but you might be surprised by how many acronyms and intialisms you do use on a daily basis—and by their origins.
Some are fairly straightforward. For example:
BRB: Be right back
FWIW: For what it’s worth
HTH: Hope that helps
IDK/IDEK: I don’t know/I don’t even know
IIRC: If I recall correctly
IMO/IMHO/JMHO: In my opinion/In my humble opinion/Just my humble opinion
KWYM/KWIM: Know what you mean/know what I mean
OTOH: On the other hand
TMI: Too much information
TIA: Thanks in advance
TTYL: Talk to you later
WTG: Way to go