The paper looks into the vague reference expressed in speech and gesture distribution in expository discourse. The research data are the monologues of 19 participants with total length of 2 hours 38 minutes. In these monologues, the use of vague reference (expressed in placeholders and approximators, with total amount of 2528) and functional gesture types (deictic, representational, pragmatic and adaptors, with total amount of 2309) was explored, with the aim of identifying the regular patterns of speech and gesture distribution and co-occurrence. The multimodal regularities include 1) the proportional frequency of four gesture types use equal to 6.8 / 14.4 / 28.7 / 50.1, which manifests overall distribution of co-speech gesture in expository discourse, 2) the significant difference in co-speech gesture use with placeholders and approximators which manifests itself in the use of three gesture types, adaptors, representational and pragmatic gestures, 3) the individually maintained significant difference in co-speech gesture use with placeholders and approximators which manifests itself in adaptors. These regularities can serve as predictors for identifying the specifics of vague reference in multimodal expository discourse.