Meanings of say thickly in English

I heard Mr. Riddle's voice say thickly, amid the silence that followed:-

Finally, he succeeded in clearing his throat to say thickly, 'Chaur... welcome back.'

He will then advance to the footlights, and, rubbing his pillow and ducking his knees to denote joviality, will say thickly through his false beard:

The soldier said thickly: No, madame; in the trenches we have tea enough.

Richie said thickly, 'The man lived for an hour or so.

The other woman said thickly, 'He died two days ago.

Then he said thickly, 'Jib an' fore tops'l, driver too.

Joe said thickly: Everything was dumped but the pilot gyros.

He stopped and said thickly: "How long were they in the pavilion?"

The Chief said thickly: Joe, somehow I don't think this is going to work.

As if speaking from far away he said thickly, "So you came, Richard."

He said thickly, 'I've never run from an enemy.

She stood by the door, and said thickly:

Munn said thickly, "What is it y... you w... want?"

Presently, with his eyes closed, he said thickly:

I'm a man in love, he said thickly.