Simple but Uncommon Chinese Characters

There are Chinese characters which are structurally simple, but not in common use today.

A perfect example is 屾 shen1, a literary term which means "并列的两座山" ("two mountains side by side".) This is one of relatively few characters that is actually ideographic, i.e. has a shape depicting the real-world concept it represents. This is because 屾 shen1 is made up of two side-by-side copies of the character for mountain, 山 shan1. Two mountains side-by-side in the character; "two mountains side-by-side" for the meaning.

Below are other characters which have piqued my interest.

• 卞 bian4"hurried": does not show up in any words on [MDBG](www.mdbg.net/chinese/dictionary?wdqb=c%3A%2A%E5%8D%9E%2A&wdrst=0]
• 惢 suo3: not even in MDBG's dictionary at all. I believe MDBG is backed by CC-CEDICT, like most Chinese dictionary services. Suo3 shows up in Pleco but without any definition or other information; extended dictionary options may give me some information.
• 勹 bao1: another Kangxi radical.
• 彳 chi4: known as 双人旁 shuang1ren2pang2, "two-person radical", by analogy with the radical form of 人 "person" called 单人旁 dan1ren2pang2 "one person radical" which is like chi4 without the upper falling stroke. I understand why Kangxi radicals have pronounceable names, but has chi4 ever been used as a character outside the radical lists?
• 亍 chu4：not a Kangxi radical. What's the origin of this one? Was it ever a shorthand version of 行? It's similar to 示.
• 2020-09-25T14:58:24-0700 AHA!! 彳 and 亍 are used together in the word 彳亍, a literary term meaning "amble; stroll." Note that the character 行, which includes "walk, move" among its many meanings, looks just like 彳 and 亍 put together.
• 卢矢 lu2shi3: "black arrow". Unlike previous entries on this list, these characters would likely be understood by moderns; I just wanted to make a note of them since neither lu2 nor shi3 are the words used for "black" and "arrow" in modern Chinese. (The corresponding characters would be 黑 hei1 and 箭 jian4.) (2020-09-11T19:11:16-0700: Student's Dictionary of Classical Chinese informs me that 矢 is the earlier character, and indicates arrows made of bamboo, while 箭 came later, and refers to arrows made of wood.)
• 雫: not even the pronunciation is in MDBG. This character occurs in the title of a Taiwanese comic series, Drops of God, so I know it can mean "drop" (of liquid).
• 足: MDBG claims that ju4 "excessive" is an alternate reading for this character, normally pronounced zu2 with meanings including "foot" and "sufficient." I can't find a reference to the ju4/"excessive" reading anywhere, even in the quite-comprehensive Student's Dictionary of Classical Chinese.