Related Clues:

• East-ender's house, say, might not have one
• Sound of puff adder's fellow creature, enraged
• Say the 'h' in 'historical,' say
• Like illegal broadcaster to pronounce his aitches
• Don't drop one's aitches like Captain 'Ook, for example
• Say “hey,” say
• Sound of an h
• Say how, for example, snake gets angry
• H, perhaps, in the role of buccaneer?
• Like “Hook”, say, pronounce the H
• Letter required when appropriate?