To find the 21st term of the sequence \(-3, 2, 7, \ldots\), first determine the common difference of the arithmetic sequence.

1. Find the Common Difference:

\[
\text{Common difference} = 2 - (-3) = 5
\]

2. Use the Formula for the \(n\)th Term of an Arithmetic Sequence:

\[
a_n = a_1 + (n - 1) \cdot d
\]

where \(a_1\) is the first term, \(d\) is the common difference, and \(n\) is the term number.

For this sequence:
\[
a_1 = -3
\]
\[
d = 5
\]
\[
n = 21
\]

3. Substitute the Values into the Formula:

\[
a_{21} = -3 + (21 - 1) \cdot 5
\]
\[
a_{21} = -3 + 20 \cdot 5
\]
\[
a_{21} = -3 + 100
\]
\[
a_{21} = 97
\]

Thus, the 21st term of the sequence is 97.