The most common and most likely answer to this crossword clue is the 10 letter word STREAMLINE
I've seen this crossword clue in The Daily Telegraph
S
T
R
E
A
M
L
I
N
E
More clues leading to the result STREAMLINE
- Get more efficient in the morning to crack Listener somehow
- Junk mail re-sent to cut out waste
- Improve speed of download online
- Make simple cooked meal in Australian English
- Make more efficient version of metal siren
- Road trips Elaine and Mary alternately take to become more efficient
- Run railway to increase efficiency
- Make more efficient power cable, getting round resistance
- Make smooth run in heritage railway?
- Make more efficient floundering men’s retail
Buddy explains!
The straight part
We know that "Make smooth" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case make smooth = streamline.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does STREAMLINE mean?
STREAMLINE noun- A line that is tangent to the velocity of flow of a fluid; equivalent to the path of a specific particle in that flow.
- On a weather chart, a line that is tangent to the flow of the wind.
- To design and construct the contours of a vehicle etc. so as to offer the least resistance to its flow through a fluid.
- (by extension) To simplify or organize a process in order to increase its efficiency.
- To modernise.