Ingrain is the dictionary-recommended spelling of the verb meaning to impress deeply. Engrain is an accepted variant, but it appears only rarely. It does not have any meanings of its own.
The preference for ingrain extends to ingrained, which is actually more common than the uninflected form. Both ingrained and engrained are listed in dictionaries, but some readers will consider engrained a misspelling.
Examples
Ingrained is preferred throughout the English-speaking world. Here are a few examples of the word in action:
The music is so ingrained in the Christmas routine that it can be hard to hear it amid the holiday hubbub. [NY Times]
But snow-readiness is as deeply ingrained in the national psyche as it is in the statutes. [The Guardian]
But being so deeply ingrained in the department he now leads has come at a cost, Beck said. [LA Times]
But engrained is not completely absent. We find quite a few instances in American publications—for example:
So engrained in the English psyche have the horrors of the Gabba become in recent years … [Wall Street Journal]
That’s a tough sell, because few things are more deeply engrained in human nature than the impulse to punish enemies. [NY Times]
Still, ingrained is far more common everywhere.
