When expressing the idea of an unspecified or indefinite level of something, there are a variety of synonyms that could be used in place of "a certain degree." For example, one might say "to some extent," "to a certain extent," "to some degree," "to a certain degree," "partly," "somewhat," "moderately," "fairly," "reasonably," "relatively," "comparatively," "marginally," "slightly," "minimally," or "to a limited extent." Which term is chosen may depend on the nature of what is being discussed, the context of the conversation, or the personal style of the speaker or writer.