what does furtive mean?

[Azazello]

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #87 "Verbal Test", question 4

It was quite obvious from the secretive manner in which he left the shop and the ......... looks he kept giving that he hadn't paid for the items of clothing.

(a) furtive
(b) fugitive
(c) furious
(d) famous

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #87 "Verbal Test", answer 4

It was quite obvious from the secretive manner in which he left the shop and the furtive looks he kept giving that he hadn't paid for the items of clothing.

Correct answer: (a) furtive
_________________________

could you please explain the sentence?

Azazello

[BuddhaGeo]

Here is what dictionary.com has to say.