As zhōng, 中 covers three threads: spatial middle (中间, 中心), being inside or among a group (其中, 空中), and an ongoing state (进行中, in progress). All flow from the core image of being at the center or within.
mistakes
中 has two readings. zhōng (1st tone) = middle / within / China (中国, 中文, 其中). zhòng (4th tone) = to hit a target / be struck by (中奖, 中毒). If the verb means 'hit' or 'win,' it's zhòng — almost everything else is zhōng.
The long vertical piercing the box from top to bottom, pinpointing the exact center. The arrow-through-target image gives 中 both senses: 'middle / center' (zhōng) and 'to hit the mark' (zhòng). Indexed under Kangxi #2 丨 (the line radical).
The boxy outer frame, read here as a target or enclosed area rather than a literal mouth. Three strokes form the rectangle that the vertical line will pierce dead-center, setting up the 'middle / center' image.
Literally 'Middle Kingdom' — the self-name treating China as the center of the civilized world. Same 中 in 中文 (Chinese language) and 中医 (traditional Chinese medicine).
