each other; one another
彼 (bǐ) · 8 strokes
Phonosemantic compound. 彳 represents the meaning and 皮 represents the sound.
此 (cǐ) · 6 strokes
Origin unclear. Two possible explanations are (1) depicts a person (人) stopping (止), meaning "here", and (2) depicts a foot (止) kicking a person (人), based on an earlier meaning "to kick" (跐).