The word "precessional" refers to a spinning or rotating movement that happens before another movement. It means that one rotation or spin occurs before the expected or usual one. Full definition
Earth eccentricity cycles modulate the amplitude of precessional forcing of the African monsoonal rains (see upper right panel), and deep lake conditions are observed in several East African basins during some (not all) eccentricity maxima over the 5 Ma (deMenocal, 2011; Trauth et al., 2005; Kingston et al., 2007) (ldeo.columbia.edu)
I am assuming the similarity of the «low eccentricity and consequently weak precessional forcing» in the current interglacial and during MIS 11. (realclimate.org)
The climate change in this period is generally believed to be associated with precessional changes in the distribution of solar radiation, which primarily affect land - sea temperature contrast, and give only a regional warming, plus an enhancement of certain monsoonal circulations. (realclimate.org)