The Grok-Groot Razor is a student thing that says whether something is explaining or just describing shit.
"Grok" is knowing some actual mechanism; Einstein said "matter bends space & time", which explained all of Newtons formulas in a single sentence. "Groot" on the other hand is usually a formula about relationships, but without explaining what's actually physically happening. Ohm's Law is Groot; math that to calculate voltages and resistance etc. while saying nothing about what electricity actually is. Most of physics is just groot.
Teachers love to make you memorize groot by rote, without ever getting to the grok that lets you really understand something.
I hate memorizing all these grooty formulas!
I grok it now!
Opposite of square. Groovy is originally an expression from jazz, meaning musical, playable, as in a groovy record. The groove of the record has beat and soul. Something or someone groovy has beat and soul. The term was adopted by the musically inclined countercultures of beatniks and hippies.