MCSP can refer to: Merlin Capability Sustainment Plus: Mid-Life Update of Merlin (see Lockheed Martin U.K. and AgustaWestland EH101) Melanoma-associated chondroitin sulfate proteoglycan, a tumour marker Member of the Chartered Society of Physiotherapy Minimum cost spanning tree, the lowest costing way to construct a spanning tree graph. Multichannel Serial Port: A subsystem of Texas Instruments TMS320 DSPs.