titter

verb

1. To laugh or giggle in a somewhat subdued or restrained way, as from nervousness or poorly-suppressed amusement.

   “1863, Henry Wadsworth Longfellow, Tales of a Wayside Inn Part First: The Sicilian's Tale - King Robert of Sicily A group of tittering pages ran before.”

   “"Thou coxy, cackling candle!" said Catweazle. "Why dost thou titter?"”

   “Nor had the joke been a vulgar one: it was the kind of elegant pleasantry that the minister of foreign affairs might have told the crown prince at a garden party a generation ago, causing the surrounding listeners to titter with delight.”

2. (obsolete)To teeter; to seesaw.

noun

1. A nervous or somewhat repressed giggle.

   “April 21, 1811, Samuel Taylor Coleridge, Table Talk There was a titter of […] delight on his countenance.”

2. (in-plural, slang, vulgar)A woman's breast.

   “Flesh Gordon 2 - I remember that this one was chock full of big titters. Many of them looked like the natural variety, as well.”

   “there was an old lady from raleigh who was so doggone nasty by golly just squeezin her titters you'd pick up some critters and bathe twice in one month for your folly”

   ““The poor dear, even her titters are weighted down with melancholy,” Pearle said to Mable. “I don't know what you're talking about. Her titters look perky enough to me,” Mable replied.”

3. (obsolete, slang)A girl or young woman.

   “David […] was a man peculiarly after God's own heart, had plenty of wives, and, when he got old and shaky, and there were doubts about his virility, the prophet of the Lord told him to go and get a young "titter" — a capable young woman — to test him, and see if the fires of his passion had gone out, and to keep him warm if they had. There is the Bible for you.”