The most common and most likely answer to this crossword clue is the 9 letter word IMPEDANCE
I
M
P
E
D
A
N
C
E
More clues leading to the result IMPEDANCE
Buddy explains!
The straight part
We know that "Obstacle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case obstacle = impedance.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 IMPEDANCE mean?
IMPEDANCE noun- The act of impeding; that which impedes; a hindrance.
- A measure of the opposition to the flow of an alternating current in a circuit; the aggregation of its resistance, and inductive and capacitive reactances; the ratio of voltage to current treated as complex quantities.
- A quantity analogous to electrical impedance in some other energy domain
- (by analogy, usually with “mismatch”) a measure of the opposition caused by differences between two paradigms, especially between object-oriented development and relational databases