号

Source: Make Me a Hanzi.

号 shows a mouth 口 with a line spilling out, as if crying out. That gave the first sense 'to wail, cry out.' The line is now written 丂, which also gives the sound. The meaning grew to 'to call', 'name', 'mark', 'number', 'horn', and 'to command.'

Drawn as: mouth with line