口
Means mouth, opening
[1]
 
Memory hook Resembles an open mouth.
Grammar Note
The character 口 often appears as a part in characters that have to do with the mouth or speaking.
Combinations
ChineseliterallyEnglish
人口person mouthpopulation ⓘthe number of people or human mouths to feed
Practice
ChineseliterallyEnglish
口好mouth goodThe mouth/opening is ok.
人口好population goodThe population is good.
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[1] open mouth;teeth by user Marfuas from http://commons.wikimedia.org/wiki/File:Marfuas.jpg under license: Public domain