Fric-tion frik-shuhn noun.
Surface resistance to relative motion, as of an item sliding or rolling: the resistance felt when one object is moved against another (or through liquid or gas)
Example: There is friction between the wheels of a car and the road-surface.
Rose closed her eyes and wished she could cover her face with her hands but she couldn't open her clenched fingers as they desperately gripped the railings.
"We're gonna die, we're gonna die!" she chanted in pure panic.
"We are not going to die!" the Doctor yelled at her from his place against the console, flipping switches and pumping levers. A sudden jolt had him falling against the hexagonal console and sliding quickly to the floor. He scrambled to his knees and reached for the hard wooden mallet.
"Probably not going to die," he amended, "should have said probably there."
Dissension or conflict between persons, nations etc, because of differing ideas, wishes, etc. quarrelling; disagreement
Example: There seems to be some friction between the workmen and the manager.
The Doctor crossed his arms and watched as Rose headed off to bed. He turned back to the pretty boy currently occupying his ship.
"Okay, Captain Jack, this is my ship—the TARDIS and there're rules."
"Of course."
"No flying or attempting to fly her. No eating in the control room, no orgies, no battles, no bacchanals and definitely no domestics."
"And the blonde?"
"Off limits."
Jack sighed. "Any leeway on any of those?"
The Doctor thought about it. "Only if I die then we'll negotiate."
"And Rose?"
"Not even then," he smirked, "you never know, I might be back."
The rubbing of the surface of one body against another: the rubbing together of two things
Example: The friction between the head of the match and the matchbox causes a spark.
Another bumpy ride as the Doctor tries to show Rose how to fly the TARDIS.
She's cradled in his embrace, one hand on either side of her waist as the TARDIS jumps in the vortex. He holds tight to Rose, pressing his chest against her back.
His leg slides between hers, bracing her, trapping her.
Her breathing is ragged and she looks heatedly over her shoulder. His temperature soars.
He inadvertently grinds his hips against hers and her eyes widen as she turns in his arms.
"Flying lesson?"
"Maybe later," he growls and fuses his mouth to hers. "Much later."