agostic interaction

The manner of interaction (termed according to the Greek 'to hold or clasp to oneself as a shield') of a coordinatively unsaturated metal atom with a ligand, when the metal atom draws the ligand towards itself. An important type of agostic interaction is the C–H–Metal coordination providing for the activation of the C–H bond in transition metal complexes.
Source:
PAC, 1999, 71, 1919 (Glossary of terms used in theoretical organic chemistry) on page 1922