Alexander is just Alex with a wierd r in the air. Was your family foreign?

Seeing as they use your abriviation 'd' for 'ed', and also in 'Chapely d' abriviating 'chapel yard', and 'Alex r' for Alexander, maybe its a name that ends with 'd'?

On the other hand, looking how other names are abbriviated may help....

Alex/Alexr - Alexander
Bernd - Bernard
Chas - Charles
Dy/Do - Dorothy
Edw - Edward
Eliz - Elizabeth (not to be confused with Eliza)
Em - Emma/Emily
Fredk - Frederick
Geo - George
Hon - Honour
Hum/Humy - Humphrey
Jas - James
Jno - John
Jonth - Jonathon
Jos - Joseph
Josh - Joshua/Joseph
Marg - Margaret (not Mary)
Mart - Martha (not Margaret)
Mattw - Matthew
My - Mary
Ric/Richd - Richard
Robt - Robert
Saml - Samuel
Ste - Stephen
Tam - Tamsin/Thomasin
Tho/Thos - Thomas
Wm - William
Xian - Christian
Xpr - Christopher

http://www.woodgate.org/FAQs/socgbrit.html#FAQ12