What does it mean if you lose pressure on your clutch?

Can mean a few things. Low hydraulic fluid( brake fluid) in clutch master cylinder, worn clutch disc, needs bleed, slave cylinder slowly losing seal, seals in master cylinder, linkage problem. It could go forever but it is probably just the clutch disk material. To sum it up it means take it to the shop because if you don't know what it could be you most likely don't know how to fix it and it will only get worse to the point where it will not move