What could 1NT mean opposite a partner's takeout double?
Absolutely not - just bid 2C (in tempo so as to not present partner with an ethical problem).

The hand you are attempting to protect against, a balanced 12-14 count, is explicitly denied by partner's take-out double. If partner has that range then a singleton small Spade is almost guaranteed; a doubleton at most absolutely guaranteed. 

Likewise partner does not have a 15-18 point hand with a spade stopper, as that hand has been denied by the failure to overcall 1NT. 

Further, the 4333 distribution with an empty 4-card suit is deadly. This hand could easily play two or more full points weaker than its alleged 11 HCP if partner does not have at least 4 diamonds.

Since there is no right call to make with this hand, as all possibilities and the hand itself have significant flaws, follow the Golden Rule: Never overbid a bad hand. Just bid a craven 2C as recommended.