ad·es·sive 
(ăd′ĕsĭv)
(ăd′ĕsĭv)adj.
Of, relating to, or being the grammatical case expressing means, as Finnish puhumalla "by speaking, while speaking."
n.
1. The adessive case.
2. A word in the adessive case.
[From Latin adesse, to be present : ad-, ad- + esse, to be; see es- in the Appendix of Indo-European roots.]