ADDTO

• Acquire more items for, as a collection

• Append

• Augment

• Beef up

• Boost

• Build an extension on

• Build on

• Build up, as a collection

• Buy another item for, as a collection

• Embellish

• Enhance

• Enlarge

• Enlarge, as a lead

• Enlarge, as one's lead

• Expand upon

• Expand, as a collection

• Heighten

• Include in, as a recipe

• Increase

• Increase by

• Increase, as a lead

• Increase, as the pot

• Lengthen, as a lead

• Make it bigger

• Pad

• Pile on

• Put in

• Supplement

• Throw in