portcullis /pōrt- or pört-kulˈis/

1. A grating that can be let down to close a gateway of a castle, fortress, etc
2. A lattice (heraldry)
3. One of the pursuivants of the English College of Heralds
4. An Elizabethan silver halfpenny with a portcullis on the reverse

To obstruct, as with a portcullis

• at one's elbow
• at one's finger-ends
• at one's finger's-ends
• at one's fingertips
• at one's leisure
• at one's wit's end
• at one time
• atonic
• atonicities
• atonicity
• atonies
• atoning
• atoningly
• atony
• atop
• atopic
• atopies
• a top noise
• atopy
• atorvastatin
• atorvastatins
• a touch of the sun
• a tough nut to crack
• at outs
• ATP