Definition: Be aware of through observation, inquiry, or information.
ASL student tip: Not to be confused with the sign THINK. It's not uncommon that students mix up KNOW with THINK.
Trivia: The origin of KNOW came from a compound KNOW+BRING (anticipatory assimilation).
It's often a sentence opener as in "Did you know that..." or "Know that...". Raise eyebrows for the yes/no question "did you know that".
First 100 words.
As you feel more comfortable with the first few hundreds of ASL signs, progress further with your vocabulary and learn signing more.