Tyro is a perfectly good english word meaning a beginner in learning anything, a novice from Latin tiro (recruit). Know the word, have never heard it on RT or seen it in any manuals in US.
Students or people with less ability/equipment than may be expected (in IMC without a instrument ticket perhaps) are encouraged to identify themselves when they climb and confess and yell for help. Think it is done mainly with more Anglo-Saxon words than Latin ones, though.