Thank you for bringing this to our attention. It is incorrectly labelled in the Functional Annotation Clustering options and should be labelled "Fold Enrichment" which will match the option in the Functional Annotation Chart.
"Fold Enrichment" refers to the enrichment of the term in your gene list as compared to the background population of genes.
For example, if 40/400 (i.e. 10%) of the genes from your list are involved in "kinase activity" and the background population ratio of genes involved in "kinase activity" is 300/30000 genes (i.e. 1%). There is a 10-fold(10%/1%) enrichment of genes from your list involved in "kinase activity" compared to the population.