1) It's an obvious typo for "ill at ease." OCR scanning software can easily mistake a "c" for an "e", or vice versa.
2) "Ill at ease" means "socially uncomfortably," "slightly anxious," "unsure." It is the opposite of "confident," "poised," or "self-assured."
A person on their first date with someone might feel ill at ease.
Many people feel ill at ease when speaking to a large group.
A person who is ill at ease might fidget or might act tense and awkward.