unawares

• He drank deep at the fountain of inspiration unawares, and manhood found him ready to follow those who beckoned to him from the pages of history Rodolphe Töpffer was born at Geneva on the seventeenth day of February, 1799. —  The Atlantic Monthly, Volume 16, No. 97, November, 1865
• But I knows a clean place when I takes it unawares, and clothes with more patch than stuff, and all the colour washed out of them, and bruises hid, and a bad husband made the best of, and children as knows how to behave themselves The warmth of Mrs. Bundle's feelings only prompted me to tease her; and it was chiefly for "the fun of working her up" that I said Ah, but, Nurse, you know we heard she went after him one night to the public-house, and made a row before everybody. —  A Flat Iron for a Farthing or Some Passages in the Life of an only Son
• Neither will nor thought can keep one of these waves from suddenly breaking upon us; and we shall be caught unawares, and perhaps be wounded and stunned. —  The Buried Temple
• But the last thing the Indians will expect is the appearance of a boat-load of armed men at this hour, and to take the enemy unawares is the essence of good generalship When am I to have my letter?" —  The Captain of the Kansas
• But Uncle Tomas was not the man to be taken unawares, and reversed the surprise, striking Espartero with a small force in the darkness, and driving back his men in confusion and dismay. —  Historical Tales - The Romance of Reality - Volume VII

Roget's II: The New Thesaurus