To Not Be Sufficient, To Not Be Enough, Insufficient, Not Sufficient, To Be Insufficient
Intransitive verb
たりない
お金が十円足りないんです。
I’m ten yen short.
もしスペースが足りなければ、べつの用しについきして、それをてんぷしてください。
If there is insufficient space, attach a separate sheet with additional information.
ビル・ゲイツは私の息子なのだが、それを証明するための証拠がまだ足りない。
Bill Gates is my son, but there isn’t enough evidence to prove it yet.
You know the word 足りる from Level 4. What is this one? it's the opposite (negative form on a verb is ない). So, what is the opposite of 足りる (To be sufficient)? The opposite is to not be sufficient or not enough.
The reading is the same as 足りる (たりる) which you should have seen in Level 4.