experiencing or accompanied by sleeplessness; "insomniac old people"; "insomniac nights"; "lay sleepless all night"; "twenty watchful, weary, tedious nights"- Shakespeare
the quality of being consistent with or based on logic
the state of having good sense and sound judgment; "his rationality may have been impaired"; "he had to rely less on reason than on rousing their emotions"
a precautionary measure warding off impending danger or damage or injury etc.; "he put an ice pack on the injury as a precaution"; "an insurance policy is a good safeguard"; "we let our guard down"