credibilize
/ˈkrɛdɪbɪlʌɪz/ /ˈkrɛdɪb(ə)lʌɪz/(also credibilise)
verb
[with object] To make credible or more credible, increase the credibility of.
Origin
Mid 19th century. From classical Latin crēdibilis credible + -ize, probably after credibilizing.