1. 可允许的；可准许的；可容许的
If people decide that something is allowable, they let it happen without trying to stop it.

e.g. Capital punishment is allowable only under exceptional circumstances.
只有特殊情况才允许执行死刑。

2. （费用等）免税的
Allowable costs or expenses are amounts of money that you do not have to pay tax on.

e.g. Her expenses were allowable deductions.
她的费用开支是免税的。

adj

1. deductible according to the tax laws

2. that may be permitted especially as according to rule

e.g. permissible behavior in school
a permissible tax deduction

Synonym: permissible

3. deserving to be allowed or considered