Snd= Sound. The connotations of Sound in slang are, cool, fine, nice, affirmitive.

When someone goes to the gym and spends 90% of the time on their phones scrolling through social media

A slang word for the gamemode Search and Destroy played in Call of Duty.

Sunday night depression.
When you feel sad because your weekend is over and you have work/school the next day.

SNDS, "Sudden Northwood Death Syndrome," refers to the vulnerability of Intel's Pentium 4's "Northwood" class processors to overclocking. Overclockers soon realized that after 1.7 volts, the processor would become gradually unstable, and eventually be completely unusable. The rate at which this happens varies entirely from processor to processor. That is, to say, it could take days, or even months, but it always happens, and always occurs at 1.7 volts (or higher, which obviously accelerates SNDS). Once a processor has contracted SNDS, the prognosis is very grim. Even if you return the core (CPU) to stock speeds, the damage is already done, and could even still progress at stock voltage. Overclocking is a great way to improve hardware, but it can be dangerous and has its risks... only attempt to do so if you have a strong background in computer science.

S'n D is an abbreviation for "Suckin Dick"

The D can be replaced with the first letter of any other body part.

B=Butt
V=Vagina