the act of fastening things together

bonding / soldering - fastening firmly together
doweling - fastening by dowels
grounding / earthing - fastening electrical equipment to earth
linkage - the act of linking things together
tying / ligature - the act of tying or binding things together
welding - fastening two pieces of metal together by softening with heat and applying pressure
fixation - the activity of fastening something firmly in position

    joining     connection     connexion

the act of attaching or affixing something

graft / grafting - the act of grafting something onto something else

    combination     combining     compounding

faithful support for a religion or cause or political party

ecclesiasticism - excessive adherence to ecclesiastical forms and activities
kabbalism / cabalism - adherence to some extreme traditional theological concept or interpretation
royalism - adherence or attachment to a monarchy or to the principle of monarchal government
traditionalism - adherence to tradition (especially in cultural or religious matters)

    support

a supplementary part or accessory

    addition     add-on     improver

a connection that fastens things together

ligament - any connection or unifying bond

    connection     connexion     connector     connecter     connective

a writ authorizing the seizure of property that may be needed for the payment of a judgment in a judicial proceeding

    writ     judicial writ

a feeling of affection for a person or an institution

    affection     affectionateness     fondness     tenderness     heart     warmheartedness