【Relevant】 , 【germane】 ,  【material】 ,  【pertinent】 ,  【apposite】 ,  【applicable】 ,  【apropos】  are comparable when they mean having a relation to or a bearing upon the matter in hand or the present circumstances.

Something  【relevant】 has a traceable connection, especially logical connection, with the thing under consideration and has significance in some degree for those who are engaged in such consideration.

Something  【germane】 is so closely related (as in spirit, tone, or quality) to the subject, the matter, the occasion, or the issue that the fitness or appropriateness of their association is beyond question.

Something  【material】 is so closely related to the matter in hand that it cannot be dispensed with without having an evident and especially a harmful effect.

Something  【pertinent】 is so decisively or significantly 【relevant】 that it touches the real point at issue or contributes materially to the understanding of what is under discussion or to the solution of what is in question.

Something 【apposite】 is 【relevant】 and 【germane】 to such a degree that it strikes one both by its pertinency and by its felicitousness.

Something  【applicable】 may be brought to bear upon or be used fittingly in reference to a particular case, instance, or problem.

Something  【apropos】 is both appropriate and opportune.

Sometimes it can suggest relevancy rather than appropriateness or opportuneness.