timid

(noun) people who are fearful and cautious. Synonyms: cautious. Example: "Whitewater rafting is not for the timid."

(adj) showing fear and lack of confidence. Synonyms: timid (vs. bold).

(adj) lacking self-confidence. Synonyms: diffident (vs. confident), shy, unsure. Examples: "Stood in the doorway diffident and abashed." "Problems that call for bold not timid responses." "A very unsure young man."

(adj) lacking conviction or boldness or courage. Synonyms: faint, fainthearted, faint-hearted. Example: "Faint heart ne'er won fair lady."