diff --git a/promql/functions.go b/promql/functions.go
index 8e9e6f9654..d481cb7358 100644
--- a/promql/functions.go
+++ b/promql/functions.go
@@ -302,7 +302,7 @@ func funcHoltWinters(vals []parser.Value, args parser.Expressions, enh *EvalNode
 	// The trend factor argument.
 	tf := vals[2].(Vector)[0].V
 
-	// Sanity check the input.
+	// Check that the input parameters are valid.
 	if sf <= 0 || sf >= 1 {
 		panic(fmt.Errorf("invalid smoothing factor. Expected: 0 < sf < 1, got: %f", sf))
 	}
diff --git a/promql/parser/parse.go b/promql/parser/parse.go
index 7a0e48464b..6c37ce6fc6 100644
--- a/promql/parser/parse.go
+++ b/promql/parser/parse.go
@@ -432,7 +432,7 @@ func (p *parser) expectType(node Node, want ValueType, context string) {
 	}
 }
 
-// checkAST checks the sanity of the provided AST. This includes type checking.
+// checkAST checks the validity of the provided AST. This includes type checking.
 func (p *parser) checkAST(node Node) (typ ValueType) {
 	// For expressions the type is determined by their Type function.
 	// Lists do not have a type but are not invalid either.
diff --git a/promql/test.go b/promql/test.go
index 41526ccdc5..ab2a159c4e 100644
--- a/promql/test.go
+++ b/promql/test.go
@@ -491,8 +491,8 @@ func atModifierTestCases(exprStr string, evalTime time.Time) ([]atModifierTestCa
 	})
 
 	if containsNonStepInvariant {
-		// Since there is a step invariant function, we cannot automatically
-		// generate step invariant test cases for it sanely.
+		// Expression contains a function whose result can vary with evaluation
+		// time, even though its arguments are step invariant: skip it.
 		return nil, nil
 	}
 
diff --git a/tsdb/agent/db.go b/tsdb/agent/db.go
index 9574c4b8a0..0675d5a287 100644
--- a/tsdb/agent/db.go
+++ b/tsdb/agent/db.go
@@ -77,7 +77,7 @@ type Options struct {
 	NoLockfile bool
 }
 
-// DefaultOptions used for the WAL storage. They are sane for setups using
+// DefaultOptions used for the WAL storage. They are reasonable for setups using
 // millisecond-precision timestamps.
 func DefaultOptions() *Options {
 	return &Options{
diff --git a/tsdb/db.go b/tsdb/db.go
index d18f4fee63..7a165e431b 100644
--- a/tsdb/db.go
+++ b/tsdb/db.go
@@ -66,7 +66,7 @@ const (
 // ErrNotReady is returned if the underlying storage is not ready yet.
 var ErrNotReady = errors.New("TSDB not ready")
 
-// DefaultOptions used for the DB. They are sane for setups using
+// DefaultOptions used for the DB. They are reasonable for setups using
 // millisecond precision timestamps.
 func DefaultOptions() *Options {
 	return &Options{
diff --git a/tsdb/head_append.go b/tsdb/head_append.go
index 8de71114fb..d5003188d2 100644
--- a/tsdb/head_append.go
+++ b/tsdb/head_append.go
@@ -440,7 +440,7 @@ func (s *memSeries) appendableHistogram(t int64, h *histogram.Histogram) error {
 }
 
 // AppendExemplar for headAppender assumes the series ref already exists, and so it doesn't
-// use getOrCreate or make any of the lset sanity checks that Append does.
+// use getOrCreate or make any of the lset validity checks that Append does.
 func (a *headAppender) AppendExemplar(ref storage.SeriesRef, lset labels.Labels, e exemplar.Exemplar) (storage.SeriesRef, error) {
 	// Check if exemplar storage is enabled.
 	if !a.head.opts.EnableExemplarStorage || a.head.opts.MaxExemplars.Load() <= 0 {
diff --git a/web/ui/react-app/src/utils/utils.test.ts b/web/ui/react-app/src/utils/utils.test.ts
index 99a72d7b83..4db3e28a64 100644
--- a/web/ui/react-app/src/utils/utils.test.ts
+++ b/web/ui/react-app/src/utils/utils.test.ts
@@ -190,7 +190,7 @@ describe('Utils', () => {
       it('renders never for pre-beginning-of-time strings', () => {
         expect(formatRelative('0001-01-01T00:00:00Z', now())).toEqual('Never');
       });
-      it('renders a humanized duration for sane durations', () => {
+      it('renders a humanized duration for durations', () => {
         expect(formatRelative('2019-11-04T09:15:29.578701-07:00', parseTime('2019-11-04T09:15:35.8701-07:00'))).toEqual(
           '6.292s ago'
         );