hesitation

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The act or an instance of hesitating.
• noun The state of being hesitant.
• noun A pause or faltering in speech.

from The Century Dictionary.

• noun The act of hesitating; a pausing or delay in determining or acting; suspension of judgment or decision from uncertainty of mind; a state of doubt.
• noun An irregular involuntary pausing in speech; awkward or embarrassed interruption of speech; stammering.
• noun Synonyms Hesitation, Hesitancy; wavering, suspense, uncertainty, doubt, vacillation; faltering. Hesitation is perhaps more often used for the act of hesitating, hesitancy generally for the spirit, character, or frame of mind. Hesitation is more common.

from the GNU version of the Collaborative International Dictionary of English.

• noun The act of hesitating; suspension of opinion or action; doubt; vacillation.
• noun A faltering in speech; stammering.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An act of hesitating; suspension of opinion or action; doubt; vacillation.
• noun A faltering in speech; stammering.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun indecision in speech or action
• noun a certain degree of unwillingness
• noun the act of pausing uncertainly