to scold
咜 centers on the act of scolding: using sharp words to reprimand or rebuke someone.
咜 combines 口 (mouth) with 它, which likely contributes the sound. The mouth radical suggests a vocal action such as scolding.
The mouth 口 on the left and the shape 它 on the right look like an open mouth scolding someone. Picture a parent's mouth wide open, scolding a child.
For タ, imagine a parent scolding a child and saying 'Ta-ta! That's enough!' The sharp 'ta' sound cues タ while the mouth 口 delivers the scolding.