歪 is made of 不 (not) over 正 (straight) stacked together. Not straight equals crooked. This is one of the easiest characters to remember because its structure literally spells out its meaning.
register
In Taiwan there is an extra spoken reading wǎi, meaning to twist or sprain (an ankle). On the mainland the character is read wāi for all senses.
Top 不 (not) supplies the negation. A textbook compound ideograph: 不 (not) over 正 (straight) literally reads as not straight, hence crooked, askew, tilted. One of the most transparent semantic compounds in the language, the meaning is right there on the page.
Bottom 正 (upright, correct) supplies the standard being negated. Combined with 不 (not) above, the compound reads as not straight, hence crooked. The entry's indexing radical is Kangxi #77 止, which sits as the lower portion of 正 rather than as a visibly separable component. Same 正 anchors 政, 整, 症.
Filed under radical 止 (zhǐ, #77) by convention. 止 is not a separate component in 歪, so no strokes are highlighted.
