From Rogersmushrooms.com:
edibility: Inedible
fungus colour: Brown, Grey to beige
normal size: Less than 5cm
cap type: Convex to shield shaped
stem type: Simple stem
flesh: Mushroom has distinct or odd smell (non mushroomy)
spore colour: Pink
habitat: Found in fields, lawns or on roadsides

Cap 2-4cm, flat to domed, brownish-grey silky shiny, striate. Gills dirty white then muddy pink. Stem the same colour as the cap with a lighter apex and base. Taste and smell mild to farinaceous rancid. Spore print brownish-pink, spores angled 7.5-10x6.5-8. Grassy places sometimes as early as May or June, rare. Not edible.

From first-nature.com
A delicate pinkgill is often seen in parkland and meadows, Entoloma sericeum is occasionally seen also on roadside verges. The caps are hygrophanous, and so the shade of brown depends very much on how wet or dry the weather has been. Some specimens are even darker than those shown.

2.5 to 5cm across; initially conical, developing an umbo as it becomes broadly convex; hygrophanous, darker brown when wet and much paler, often streaky buff, when dry; surface smooth with silky radial fibrils.

Gills Sinuate; pale grey at first, becoming pinkish grey and eventually brown.

From ispot.org:
Cap dark brown grey 2-4cm gills pallid grey becoming pink with age adnexed or emarginate ,stem concolorous with cap more pallid at the apex and base with silky fibres base sightly swollen found in small group at edge of woodland track in grassy area